post请求request为流时，转化为map

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
    {
        String requestString = getRequestPayload(request);
        Map<String, String> requestMap = new HashMap<String, String>();
        requestMap = RequestInfoUtil.requestUtil(requestString);
        String requestMethod = requestMap.get("aaa");
    }

    private String getRequestPayload(HttpServletRequest req)
    {
        StringBuilder sb = new StringBuilder();
        try (BufferedReader reader = req.getReader();)
        {
            char[] buff = new char[1024];
            int len;
            while ((len = reader.read(buff)) != -1)
            {
                sb.append(buff, 0, len);
            }
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        return sb.toString();

public class RequestInfoUtil
{
    public static Map<String, String> requestUtil(String request)
    {
        Map<String, String> map = new HashMap<String, String>();
        strRequest(map, request);
        return map;
    }

    public static String strRequest(Map<String, String> map, String s)
    {
        int length = s.length();
        int index1 = s.indexOf("=");
        String parm1 = s.substring(0, index1);
        int index2 = s.indexOf("&");
        if (index2 == -1)
        {
            String parm2 = s.substring(index1 + 1);
            map.put(parm1, parm2);
            return null;
        }
        String parm2 = s.substring(index1 + 1, index2);
        map.put(parm1, parm2);
        return strRequest(map, s.substring(index2 + 1));
    }
}